有的設計人員認為(wei),只有可燃(ran)介質管道(dao)才(cai)需要(yao)(yao)靜電(dian)接(jie)地,非可燃(ran)介質(如儀表風、工(gong)廠風、氮氣等)管道(dao)不需要(yao)(yao)靜電(dian)接(jie)地,這是不正確的。
起火(huo)、爆(bao)炸(zha)發(fa)(fa)生(sheng)需要(yao)(yao)三個條件:存在(zai)(zai)可(ke)(ke)燃(ran)(ran)(ran)(ran)(ran)介(jie)質,可(ke)(ke)燃(ran)(ran)(ran)(ran)(ran)介(jie)質和氧(yang)(yang)氣(qi)(qi)接觸,存在(zai)(zai)足夠(gou)引燃(ran)(ran)(ran)(ran)(ran)可(ke)(ke)燃(ran)(ran)(ran)(ran)(ran)介(jie)質和氧(yang)(yang)氣(qi)(qi)混(hun)合物(wu)(wu)的(de)(de)火(huo)花。由靜(jing)(jing)電(dian)引發(fa)(fa)的(de)(de)火(huo)災(zai)(zai)或(huo)爆(bao)炸(zha)事(shi)故,一定是由于(yu)靜(jing)(jing)電(dian)放(fang)電(dian)產(chan)生(sheng)電(dian)火(huo)花引燃(ran)(ran)(ran)(ran)(ran)或(huo)引爆(bao)泄漏到管道或(huo)設備(bei)外部(bu)的(de)(de)可(ke)(ke)燃(ran)(ran)(ran)(ran)(ran)氣(qi)(qi)體或(huo)可(ke)(ke)燃(ran)(ran)(ran)(ran)(ran)粉塵(chen)與(yu)氧(yang)(yang)氣(qi)(qi)的(de)(de)混(hun)合物(wu)(wu)而產(chan)生(sheng)的(de)(de)。只要(yao)(yao)存在(zai)(zai)可(ke)(ke)燃(ran)(ran)(ran)(ran)(ran)氣(qi)(qi)體或(huo)可(ke)(ke)燃(ran)(ran)(ran)(ran)(ran)粉塵(chen)集聚的(de)(de)區(qu)域,都存在(zai)(zai)因(yin)靜(jing)(jing)電(dian)放(fang)電(dian)或(huo)引發(fa)(fa)火(huo)災(zai)(zai)或(huo)爆(bao)炸(zha)的(de)(de)風險(xian)。判(pan)斷管道是否(fou)需要(yao)(yao)靜(jing)(jing)電(dian)接地的(de)(de)依據,不(bu)是其內(nei)的(de)(de)介(jie)質是否(fou)可(ke)(ke)燃(ran)(ran)(ran)(ran)(ran),而是其是否(fou)位(wei)于(yu)火(huo)災(zai)(zai)和爆(bao)炸(zha)危險(xian)區(qu)域內(nei)。SH 3097和HG 20675中有明確的(de)(de)規定,對爆(bao)炸(zha)和火(huo)災(zai)(zai)危險(xian)環境內(nei)可(ke)(ke)能產(chan)坐靜(jing)(jing)電(dian)危害(hai)的(de)(de)物(wu)(wu)體,應采(cai)取(qu)工業靜(jing)(jing)電(dian)接地措(cuo)施。
有人(ren)認(ren)為,水(shui)(shui)(shui)是(shi)導(dao)電(dian)(dian)(dian)的(de),所以(yi)水(shui)(shui)(shui)管(guan)道、蒸汽管(guan)道不(bu)(bu)需要(yao)接地(di)。事實上,蒸汽不(bu)(bu)是(shi)電(dian)(dian)(dian)的(de)良導(dao)體,水(shui)(shui)(shui)本(ben)身(shen)也(ye)不(bu)(bu)導(dao)電(dian)(dian)(dian),導(dao)電(dian)(dian)(dian)的(de)是(shi)存在導(dao)電(dian)(dian)(dian)離子(zi)(zi)的(de)水(shui)(shui)(shui)。而(er)(er)很(hen)多水(shui)(shui)(shui),如鍋爐水(shui)(shui)(shui)、除(chu)氧水(shui)(shui)(shui)、蒸汽冷凝(ning)液等(deng)都除(chu)去了大部(bu)(bu)分導(dao)電(dian)(dian)(dian)離子(zi)(zi),其導(dao)電(dian)(dian)(dian)性能并不(bu)(bu)好(hao)。即使是(shi)循(xun)環水(shui)(shui)(shui),為了減少換熱(re)設備結垢,也(ye)是(shi)經(jing)過軟(ruan)化處(chu)理,脫除(chu)了大部(bu)(bu)分的(de)鈣(gai)鎂離子(zi)(zi)。除(chu)非經(jing)過實驗(yan)證明(ming)工(gong)藝裝置所用的(de)水(shui)(shui)(shui)在管(guan)道內有良好(hao)的(de)導(dao)電(dian)(dian)(dian)性,不(bu)(bu)能認(ren)為水(shui)(shui)(shui)是(shi)導(dao)電(dian)(dian)(dian)的(de)而(er)(er)取消(xiao)爆炸和火災(zai)危險(xian)區內蒸汽和水(shui)(shui)(shui)管(guan)道的(de)靜電(dian)(dian)(dian)接地(di)要(yao)求。

